The present invention relates to toothbrushes and operating appliances therefor, and the primary object in view is to devise an improved power-operated construction for imparting to the .brush an efficient operating stroke adapted to produce the most effective cleaning act-ion. v

Accordingly we have devised an electricaloperating device to which the brush may be quickly applied and by which the proper movements will be transmitted to the brush v for actuating the bristles thereof with a quick vibratory action and in substantially straightline paths vertically,that is, longitudinally It is also sought to provide a construction of as light weight as practicable, and with the Weight of mass distributed and balanced in such a way as to provide the most effective transmission of the power from the motor device to the brush, with as little vibration of the other parts as possible, and with the result that the appliance may be conveniently handled with a minimum of effort on the part of the user or operator.

It is a further object of the invention to provide a brush handle and means of attachment thereof to the appliance of such a construction as will not only afford a secure and rigid connection but also permit as quick and convenient attachment and removal of the brush as possible.

With these general objects in View, as well as other minor objects as will appear in the course of the detailed description, the invention will now be described by reference to the accompanying drawings illustrating one form of construction which we have found to be practicable for embodying our proposed improvements, after which those features and combinations deemed to be novel and patentable will be set forth and claimed.

In the drawings- Figure 1 is a plan view illustrating a toothbrush and power-operating appliance therefor constructed in accordance with our present invention;

Figure 2 is a longitudinal sectional view, representing a section taken on a fplane indicated by the section line II-II 0 Figure 1;

Serial No; 315,234.

Figure 3 is an inverted plan view of the interior framework and parts carried thereby as illustrated in Figure 2; a

Figures 4 and 5 are enlarged detail sect1onal views, representing sections taken on planes indicated by the section lines IVIV and V-V, respectively, of Figure 2;

Figure 6 is a side view of the main operating or vibratory lever, including the crank portion of the flywheel shaft;

Figure 7 is a transverse sectional view, representing a section taken on a plane indicated by the section line VIIVII of Figure 2;

Figure 8 is a longitudinal sectional view of the handle casing;

Figure 9 is a transverse sectional view representing a section taken on a plane indicated by the section line IXIX of Figure 8;

Figures 10 and 11 are transverse sectional views representing sections taken on planes indicated by the section lines XX and XI-XI, respectively, of Figure 1;

Figure 12 is an enlarged face view of the switch-plate carried by the handle;

Figure 15 is a plan view of the bristle face of the brush and its handle; and

Figure 16 is a diagrammatic view illustrating the character of vibratory movement of the brush-head as produced by the operation of the power-actuated mechanism.

Referring now to the drawings in detail, the invention comprises, in general terms, a tooth-brush, a motor and motor case, and a handle structure intermediate the brush and motor and serving to house the operating connections for transmitting the drive action from the motor to the brush.

We make use of a brush having the usual brush-head 20 with bristle tufts 21 and a handle 22 of suitable length and adapted to be fitted into a tubular brush-holder 24. One side of the brush handle 22 is provided with akeyway 25 for receiving a rib or spline 26 formed on the interior of the holder 24, and the opposite side face of the handle 22 is provided with a concave recess 27 for engagement by a curved leaf retaining spring 28 which is secured to the holder 24 by means of a screw (see Figures 1 and 10) The holder 24 also carries a circular splash-guard 32 formed with a lug 33 which is also engaged by the screw 30, and this screw serves the further purpose of securing the holder 24 to the end of the main operating or vibrating lever 35, one side of which is also formed with a grove 36 for receiving a portion of the rib or spline 26. By this means of attachment, a firm and rigid connection is formed between the brush and the vibrating lever, as required for imparting a distinct, clearly defined vibratory action to the former.

Near its forward end the lever is fulcrumed upon a pivot pin 40 fitted with a bushing 41 and attached by means of nuts 42 to a longitudinal frame bar or extension 43 of channel cross-section as represented in Figures 3, 4 and 5. The forward end of this bar is formed with a shouldered lug 44 adapted for fixed rigid engagement with a slot 45 in a cap-piece 46 at one end of the tubular handle member 47 (of wood or other non-conducting material) which surrounds the forward end portions of the lever 35, frame bar or extension 43 and their associated parts hereinafter to be described. This cap-piece 46 is also formed with a larger slot or opening 48 (see Figure 10) for accommodating the forward end of the lever and the attached portion of the brush holder 24,-this slot being of sufficient length to permit the necessary vibratory movements of these parts.

The opposite or rear end of the frame bar or extension 43 connects integrally with the base frame 50 which is housed within a motor-case comprising upper and lower mating sections 52 and 53 suitably secured together by means of screws 54, and one end of the frame 50 being similarly secured, by a screw 55, to the lower section 53 of the motor case. The forward ends of the case sections 52 and 53 are shaped to form a circular flange 57 to embrace the corresponding end of the handle 47 ,and the handle structure is further braced and stiffened by means of a pair of tie rods 58 (Figures 2 and 7) having their forward ends threaded and secured by nuts 60 (Figure. 10) to the cap-piece 46.

The rear ends of these tie rods 58 are secured to a U-shaped yoke element 62 which is snugly seated in a semicircular and shouldered channel or groove 63 provided just inside the flange 57 of the casing sections 52 and 53 (see Figures 2 and 7).

The frame part 50 carries a motor or electric vibrator device of more or less conventional type, which may be briefly described as follows, although no claim is herein made as regards any novelty in its specific construction. The rear end portion of the lever 35 extends in position to constitute the armature member for a pair of electromagnets indicated, generally by the reference numerals 65 at opposite sides of the lever. The coils of these electromagnets are each connected in circuit with one of a pair of spring switch elements 67 on the frame bar or extension 43, and are also separately connected with independent and fixed contact points 68 forming part of a circuit-making and breaking device carried by the under side of the frame 50, and including the movable contacts 70 suitably supported by spring conductor elements 72 carried by a post 74. The spring elements 72 are alternately actuated by a cam 76 on the lower end of a shaft 77 journaled in suitable bearings and carrying a flywheel 78, access to which may be had upon occasion (as for starting the motor in case it should stop off center) through an opening 80 in the top casing section 52. Beneath the flywheel 78 the shaft 77 is formed with a crank portion 82 which is embraced within the forked rear end of the lever 35, the forked portions 84 of which are provided with screws 85 at opposite sides of the crank 82 for suitable adjustment.

An opening 88 is provided at the rear end of the motor case for passage of a flexible electric extension cord 90 to make contact with a binding post 92 (which is connected with the post 74) and also with a binding post 94 which is connected with the other switch element 67.

The switch control button 95 has a shank 96 operating within a slot 97 of the switch face plate 98 mounted on the handle member 47,'beneath which slot the shank 96 carries a button 99 somewhat longer than the slot but of the same width, thus permitting the switch parts to be inserted through the slot and then, by a quarter turn, locked in place by the shape of the button 99. The inner end of the shank 96 carries a right-angle arm or extension 100 provided with bosses 102 for sliding engagement between the spring switch elements 67 in closing the circuit; and by reference to Figure 3 it will be seen that'the elements 67 are bowed for gripping and holding the bosses 102 in circuit-closing position until the switch button 95 is positively moved by the operator in the opposite direction for opening the circuit and thereby stopping the motor.

Since the pressure exerted upon the brush in the operation of the appliance necessarily transmits a corresponding lateral thrust upon the opposite arm of the lever 35 at the rear of its fulcrum 40, an adjustable ball-bearing support is provided for the rear arm of said lever, as illustrated in Figures 2 and 5. For this purpose we provide a hardened bearing disk 105 secured to the upper face of the frame bar 43 at some distance from the fulcrum pin 40. This disk 105 cooperates with a corresponding hardened bearing disk 106 mounted within a recess 107 formed in the will be used with the same appliance, it will be convenient to mark the brushes with identifying symbols or marks, such as differently colored dots 120- (see Figure 16).

It is generally accepted that the correct method of brushing the teeth is by means of vertical or up-and-down strokes,that is, with the brush bristles following straightline paths longitudinally of the teeth. Since it is only by such movements of the brush that the bristles can be properly worked in between the teeth and food particles effectively removed, and with the least injury to the gums and the teeth themselves, the dental profession has for the most part sought to stress the merits of such a method, in contrast to the horizontal or circularmovements which are so commonly employed with positive harm to the teeth and gums. It has come to be recognized, however, how difficult it is to teach the really proper use of the brush, at least to the extent of causing the individual to become proficient in such use,sinoe it is an operation which obviously requires more painstaking effort as well as a longer time than most individuals are disposed to occupy themselves at this task. In view of these considerations it has seemed logical to conclude that if the task could be made less of a drudgeryby virtue of its consuming less effort and less time, and at the same time an undoubtedly more efficient operation made possible and without too expensive outlay, then thiswould constitute a. really genuine appeal to the average individual, with the result that a substantial progress would ac-.

tually be made in the direction of more hygienic mouth conditions and better preservation of the teeth.

In the appliance which we have devised for carrying out our purpose, it is obvious that the operation of the brush can be caused to take place in only one way, that is, the correct way, by movement of the brush bristles in substantially straight paths and lengthwise of the teeth. As illustrated by the diagram in Figure 16, the radius of movement of the brush head is so great (as compared with the amplitude of said movement) that the movement of the brush-head itself does not deviate materially from a straight line, and the path of travel of each bristle or tuft of bristles may be considered, for all ractical purposes, as a straight-line path. here are therefore none of the objections or disadvantages present which characterize the horizontal or circular brush motions attending the usual brush manipulations; and the rapidity of the vibrations of the brush as produced by the present appliance enables the brushing operation to be completed in a relatively very brief period of time.-

A very important advantage is gained by I the relative arrangement of the handle 47, the motor and the brush holder in our present construction. Obviously a tendency to vibration is set up in all such vibrator appliances, and this must be taken into account along with the factor of pressure exerted in applying the brush to the teeth in the brushing operation. In our construction, the vibrating device or motor in the motor case carried by one end of the handle provides just the proper mass whose inertia balances the eflect of the vibratory action being transmitted through the lever and handle to the brush; or, in other words, it might be said that the vibratory action is so damped or absorbed as to eliminate any noisy or clattering action, and as a result the handle itself (constituting practically the center of balance between the motor and brush), is left substantially quiet or vibrationless, and hence without any disagreeable effect upon the hand of the operator.

In this connection it may be mentioned that the lateral thrust which is transmitted through the lever, due to pressure exerted upon the brush by forcing it against the teeth, is for the most part counteracted by the A further important feature lies in the.

high mechanical efficiency of the lever arrangement with reference to the vibratory device, a long continuous lever arm being maintained between the fulcrum and the vibrator, and hence the mechanical advantage and effort exerted through the medium of said lever is correspondingly great. In keeping with this efficient operating mechanism, a proper rigidity of framework and connections is required, and we maintain such rigidity by the yoke and tie-rod connections between the motor case and handle and anchoring the framebar also in the outer end of the handle, and also by the telescoping grooved and splined connections between the lever and holder and brush-handle.

By the arrangement of the electric control switch in the side of the handle, and hence right in the grip of the operator as he makes use of the appliance, the simplest and most convenient form of control device is provided for instantaneous starting and stopping of the operation of the vibrator.

If provision were not made for preventing water, etc., from dripping down the lever v of embodiment of the improvements we desire expressly to reserve the right to make all such changes or modifications as may fairly fall within the scope of the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent, is:

1. A tooth-brush appliance comprising a tubular handle member, a motor device provided with a sectional motor-case applied to one end of said handle member, a lever fulcrumed within the handle member and actuated by said motor device, one end of said lever projecting from the other end of said handle member, and means connected with the adjacent ends of the motor-case sections and extending through the handle to the opposite end thereof and secured to said opposite end for rigidly bracing and anchoring the motor-case to the handle member.

2. A tooth-brush appliance comprising a tubular handle member, a motor device provided with a sectional motor-case. applied to one end of said handle member, toothbrush vibrating means actuated by said device and projecting from the other end of the handle member, the ends of said motorcase sections adjoining the handle member being formed with shouldered and communicating channels, and a yoke element seated in said channels and provided with tie rods extending through the handle member and rigidly anchored to the opposite end thereof.

3. A tooth-brush appliance comprising a tubular handle member, a motor-case applied to one end of said handle member, a motor device housed within said motor-case and including a frame having an extension projecting through the handle member, a cap element attached to the other end of said handle member and having said extension shouldered therein, and a vibrator arm fulcrumed upon said extension and actuated by said motor device. I

4. A tooth-brush appliance comprising a tubular handle member, a motor device attached to one end of said handle member,

a frame piece attached to said motor device and extending through the handle member,

with the corresponding end of the lever for imparting oscillatory movement thereto, a tooth-brush carried by the other end of the lever with its bristles positioned at right angles to the plane of the levers movement, and a counterthrust ball-bearing support for the lever intermediate its fulcrum and said motor device in position for counteracting the working pressure applied to the brush end of the lever in the tooth-brushing operation.

6. A tooth-brush appliance comprising a tubular handle member, a vibratory lever pivotally fulcrumed within said handle member and projecting out from the opposite ends thereof, a motor device attached to one end of the handle and operatively connected with the corresponding end of the lever for imparting oscillatory movement thereto, and a toothbrush carried by the other end of the lever.